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1.
Gynecol Oncol ; 151(1): 69-75, 2018 10.
Article in English | MEDLINE | ID: mdl-30078506

ABSTRACT

OBJECTIVE: The Post-Operative Radiation Therapy in Endometrial Carcinoma (PORTEC)-4a trial is a randomized trial for women with high-intermediate risk endometrial cancer (EC), comparing individualized adjuvant treatment based on a molecular-integrated risk profile to standard adjuvant treatment; vaginal brachytherapy. To evaluate patient acceptability and pathology logistics of determining the risk profile, a pilot phase was included in the study. METHODS: PORTEC-4a is ongoing and the first 50 patients enrolled were included in the pilot phase. Primary endpoints of the pilot phase were patient acceptance, evaluated by analyzing the screening logs of the participating centers, and logistical feasibility of determination of the risk profile within 2 weeks, evaluated by analyzing the pathology database. RESULTS: In the first year, 145 eligible women were informed about the trial at 13 centers, of whom 50 (35%) provided informed consent. Patient accrual ranged from 0 to 57% per center. Most common reasons for not participating were: not willing to participate in any trial (43.2%) and not willing to risk receiving no adjuvant treatment (32.6%). Analysis of the pathology database showed an average time between randomization and determination of the molecular-integrated risk profile of 10.2 days (1-23 days). In 5 of the 32 patients (15.6%), pathology review took >2 weeks. CONCLUSIONS: The PORTEC-4a trial design was proven feasible with a satisfactory patient acceptance rate and an optimized workflow of the determination of the molecular-integrated risk profile. PORTEC-4a is the first randomized trial to investigate use of a molecular-integrated risk profile to determine adjuvant treatment in EC.


Subject(s)
Brachytherapy/methods , Endometrial Neoplasms/therapy , Neoplasm Recurrence, Local/therapy , Patient Satisfaction , Brachytherapy/adverse effects , Disease-Free Survival , Endometrial Neoplasms/genetics , Endometrial Neoplasms/mortality , Endometrial Neoplasms/pathology , Endometrium/pathology , Endometrium/radiation effects , Endometrium/surgery , Feasibility Studies , Female , Humans , Middle Aged , Neoplasm Grading , Neoplasm Recurrence, Local/genetics , Neoplasm Recurrence, Local/mortality , Neoplasm Recurrence, Local/pathology , Neoplasm Staging , Pilot Projects , Quality of Life , Radiotherapy, Adjuvant/methods , Research Design , Risk Assessment/methods , Treatment Outcome , Workflow
2.
Eur J Surg Oncol ; 32(4): 450-4, 2006 May.
Article in English | MEDLINE | ID: mdl-16546343

ABSTRACT

AIMS: Controversial issues with respect to the treatment of patients with endometrial cancer include indications for lymphadenectomy and adjuvant radiotherapy. PATIENT AND METHODS: Between 1998 and 2004 all women with endometrial cancer stage I were included (n = 335). They all underwent total abdominal hysterectomy and bilateral salpingo-oöphorectomy. Two hundred and thirty-seven women also had a pelvic lymphadenectomy. When pelvic lymphadenectomy was performed, radiotherapy was administered only to patients with lymph-node metastases. Otherwise, adjuvant radiotherapy was based on the presence of risk factors. RESULTS: Eleven patients had lymph-node metastases. The overall absolute and relative survival-estimate at 5 years was 85.0 and 93.7%, respectively. Loco-regional recurrence was 8.5%. In the group with pelvic lymphadenectomy and negative lymph nodes these rates were 88.2, 93.9 and 5.6%, respectively. In 58 patients without any of the risk factors tumour grade III, deep myometrial invasion, or age > or =60 years, no lymph-node metastases were found. CONCLUSION: In patients with endometrial cancer FIGO stage I without risk-factors, a phenomenon which occurs in about 25% of patients with clinical stage I endometrial cancer, a lymphadenectomy can be omitted. In other patients, the debate regarding the optimal treatment will remain.


Subject(s)
Carcinoma/surgery , Endometrial Neoplasms/surgery , Lymph Node Excision/methods , Carcinoma/radiotherapy , Carcinoma/secondary , Endometrial Neoplasms/pathology , Endometrial Neoplasms/radiotherapy , Female , Humans , Lymphatic Metastasis , Middle Aged , Neoplasm Staging , Pelvis , Radiotherapy, Adjuvant , Retrospective Studies , Risk Factors , Treatment Outcome
3.
Int J Hyperthermia ; 20(1): 1-6, 2004 Feb.
Article in English | MEDLINE | ID: mdl-14612310

ABSTRACT

Based on the good results of re-irradiation plus hyperthermia in breast cancer recurrences on the chest wall, it was decided to offer similar treatment to a patient with recurrent metastatic breast cancer in the orbital region. A female patient was diagnosed in 1997 with breast cancer stage T4N0M0. She was treated with six neo-adjuvant chemotherapy courses and mastectomy, followed by hormonal treatment. In December 1998, she was diagnosed with metastatic disease in the medial upper quadrant of the left orbit. This was excised, followed by 40 Gy radiotherapy. Nine months later, the tumour had recurred in the left orbit at the margin of the radiotherapy field. This again was treated with surgery, followed by 30 Gy radiotherapy. Two months thereafter, the eyelid tumour progressed and hormonal therapy was changed, without an effect on the eyelid tumour. Screening gave no evidence of tumour activity elsewhere. The patient preferred treatment with re-irradiation plus hyperthermia to a surgical approach. Eight fractions of 4 Gy were given in 4 weeks, combined with once weekly hyperthermia. One week after treatment, the tumour had regressed completely. The patient died 22 months following treatment. Until last follow-up, a few weeks before death, the patient mentioned a dry left eye for which she used eyedrops, an unchanged vision and no further difficulties. On examination, there was epilation of the eyelids, a slight conjunctival oedema, no subcutaneous fibrosis and no evidence of tumour regrowth. For this patient, a surgical approach would have resulted in loss of the left eye. Toxicity of re-irradiation plus hyperthermia might lead to either a loss of vision or a delayed loss of her left eye due to treatment-induced toxicity. The chosen local treatment resulted in a very good palliative effect, which lasted for the patient's remaining lifetime of 22 months.


Subject(s)
Breast Neoplasms/radiotherapy , Breast Neoplasms/therapy , Eyelid Neoplasms/radiotherapy , Eyelid Neoplasms/therapy , Hyperthermia, Induced , Radiotherapy, High-Energy , Aged , Aged, 80 and over , Breast Neoplasms/pathology , Combined Modality Therapy , Eyelid Neoplasms/pathology , Female , Humans , Neoplasm Recurrence, Local , Tomography, X-Ray Computed , Treatment Outcome
4.
Int J Radiat Oncol Biol Phys ; 51(5): 1246-55, 2001 Dec 01.
Article in English | MEDLINE | ID: mdl-11728684

ABSTRACT

PURPOSE: To compare the treatment complications for patients with Stage I endometrial cancer treated with surgery and pelvic radiotherapy (RT) or surgery alone in a multicenter randomized trial. METHODS AND MATERIALS: The Postoperative Radiation Therapy in Endometrial Carcinoma (PORTEC) trial included patients with endometrial cancer confined to the uterine corpus, either Grade 1 or 2 with more than 50% myometrial invasion, or Grade 2 or 3 with less than 50% myometrial invasion. Surgery consisted of an abdominal hysterectomy and oophorectomy, without lymphadenectomy. After surgery, patients were randomized to receive pelvic RT (46 Gy), or no further treatment. A total of 715 patients were randomized. Treatment complications were graded using the French-Italian glossary. RESULTS: The analysis was done at a median follow-up duration of 60 months. 691 patients were evaluable. Five-year actuarial rates of late complications (Grades 1-4) were 26% in the RT group and 4% in the control group (p < 0.0001). Most were Grade 1 complications, with 5-year rates of 17% in the RT group and 4% in the control group. All severe (Grade 3-4) complications were observed in the RT group (3%). Most complications were of the gastrointestinal tract. The symptoms resolved after some years in 50% of the patients. Grade 1-2 genitourinary complications occurred in 8% of the RT patients, and 4% of the controls. Bone complications occurred in 4 RT patients (1%). Seven patients (2%) discontinued their RT due to acute RT-related symptoms. Patients with acute morbidity had an increased risk of late RT complications (p = 0.001). The 4-field box technique was associated with a lower risk of late complications (p = 0.06). CONCLUSION: Pelvic RT increases the morbidity of treatment in Stage I endometrial cancer. In the PORTEC trial, severe complications occurred in 3% of treated patients, and over 20% experienced mild (mostly Grade 1) symptoms. Patients with acute RT-related morbidity had an increased risk of late complications. As pelvic RT in Stage I endometrial carcinoma was shown to significantly reduce the rate of locoregional recurrence, but without a survival benefit, its use in the adjuvant setting requires careful patient selection (treating those at increased risk of relapse), and the use of treatment schemes with the lowest risk of morbidity.


Subject(s)
Endometrial Neoplasms/radiotherapy , Radiotherapy/adverse effects , Aged , Endometrial Neoplasms/surgery , Female , Humans , Middle Aged , Morbidity
9.
Int J Radiat Oncol Biol Phys ; 49(5): 1399-408, 2001 Apr 01.
Article in English | MEDLINE | ID: mdl-11286848

ABSTRACT

PURPOSE: To present the results of the dummy run of the European Organization for Research and Treatment of Cancer (EORTC) trial investigating the role of adjuvant internal mammary and medial supraclavicular (IM-MS) irradiation in Stage I--III breast cancer. METHODS AND MATERIALS: All participating institutions were asked to produce a treatment plan without (Arm 1) and with (Arm 2) simultaneous IM-MS irradiation of 1 patient after mastectomy and of 1 patient after lumpectomy. Thirty-two dummy runs have been evaluated for compliance to protocol guidelines, with respect to treatment technique and dose prescription. RESULTS: A number of more or less important deviations in treatment setup and prescription have been found. The dose in the IM-MS region deviated significantly from the prescribed dose in 10% of the cases for Arm 1, and in 21% for Arm 2. Assuming a true 5% 10-year survival benefit from optimal IM-MS irradiation, an increase of only 3.8% will be found due to this suboptimal dose distribution. CONCLUSION: In the dummy run, a number of potential systematic protocol deviations that might lead to false-negative results were detected. By providing recommendations to the participating institutions, we expect to improve the interinstitutional consistency and to promote a high quality irradiation in all institutions participating in the trial.


Subject(s)
Breast Neoplasms/radiotherapy , Lymphatic Irradiation/standards , Breast Neoplasms/pathology , Breast Neoplasms/surgery , Female , Humans , Mastectomy , Mastectomy, Segmental , Neoplasm Staging , Physical Phenomena , Physics , Practice Guidelines as Topic , Quality Assurance, Health Care , Radiotherapy Dosage , Radiotherapy, Adjuvant/standards
10.
Oncologist ; 5(6): 471-6, 2000.
Article in English | MEDLINE | ID: mdl-11110598

ABSTRACT

PURPOSE: To assess the safety, tolerance, and efficacy of transurethral surgery plus concomitant cisplatin, 5-fluorouracil (5-FU), and radiation therapy in conjunction with selective bladder preservation in patients with muscle-invading bladder cancer. Patients and Methods. Thirty-four eligible patients with clinical stage T2-T4a, Nx M0 bladder cancer without hydronephrosis were entered into a protocol aimed at selective bladder preservation. Treatment began with as complete a transurethral resection as possible followed by induction chemoradiation. This consisted of cisplatin 15 mg/m(2) i.v. and 5-fluorouracil (5-FU) 400 mg/m(2) i.v. in the mornings on d 1, 2, 3, 15, 16, and 17. On d 1, 3, 15, and 17, radiation was given immediately following the chemotherapy using twice-a-day 3 Gy per fraction cores to the pelvis for a total radiation dose of 24 Gy. Response was evaluated by cystoscopy, cytology, and rebiopsy four weeks later. Patients with a complete response received consolidation therapy with the same drugs and doses on d 1, 2, 3, 15, 16, and 17 combined with twice-daily radiation therapy to the bladder and bladder tumor volume of 2.5 Gy per fraction for a total consolidation dose of 20 Gy and a total induction plus consolidation dose to the bladder and bladder tumor of 44 Gy. Patients who did not achieve a complete response were advised to undergo prompt cystectomy, as were those with a subsequent invasive recurrence. The median follow up is 29 months. RESULTS: Of the 34 eligible patients, 26 had a visibly complete transurethral resection. One patient did not complete induction treatment due to acute hematologic toxicity. After induction treatment, 22 (67%) of the 33 patients had no tumor detectable on urine cytology or rebiopsy. Of the 11 patients who still had detectable tumor, six underwent radical cystectomy and five underwent consolidation chemoradiation (one because of refusal to have the recommended cystectomy and four because the treating institutions erroneously assigned them to receive consolidation chemoradiation rather than cystectomy). No patient has required a cystectomy for radiation toxicity. Six patients have died of bladder cancer. The actuarial overall survival at three years is 83%. The probability of surviving with an intact bladder is 66% at three years. A total of seven patients (21%) developed grade 3 or grade 4 hematologic toxicity in conjunction with this treatment. CONCLUSION: This aggressive protocol comprising local surgery plus concurrent 5-FU, cisplatin, and high-dose hypofractionated radiation has been associated with moderately severe hematologic toxicity. Longer follow-up will be necessary to assess efficacy. Both the 67% complete response rate to induction therapy and the 66% three-year survival with an intact bladder are encouraging.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Cystectomy , Urinary Bladder Neoplasms/therapy , Adult , Aged , Cisplatin/administration & dosage , Combined Modality Therapy , Female , Fluorouracil/administration & dosage , Follow-Up Studies , Humans , Male , Middle Aged
11.
Lancet ; 355(9213): 1404-11, 2000 Apr 22.
Article in English | MEDLINE | ID: mdl-10791524

ABSTRACT

BACKGROUND: Postoperative radiotherapy for International Federation of Gynaecology and Obstetrics (FIGO) stage-1 endometrial carcinoma is a subject of controversy due to the low relapse rate and the lack of data from randomised trials. We did a multicentre prospective randomised trial to find whether postoperative pelvic radiotherapy improves locoregional control and survival for patients with stage-1 endometrial carcinoma. METHODS: Patients with stage-1 endometrial carcinoma (grade 1 with deep [> or =50%] myometrial invasion, grade 2 with any invasion, or grade 3 with superficial [<50%] invasion) were enrolled. After total abdominal hysterectomy and bilateral salpingo-oophorectomy, without lymphadenectomy, 715 patients from 19 radiation oncology centres were randomised to pelvic radiotherapy (46 Gy) or no further treatment. The primary study endpoints were locoregional recurrence and death, with treatment-related morbidity and survival after relapse as secondary endpoints. FINDINGS: Analysis was done according to the intention-to-treat principle. Of the 715 patients, 714 could be evaluated. The median duration of follow-up was 52 months. 5-year actuarial locoregional recurrence rates were 4% in the radiotherapy group and 14% in the control group (p<0.001). Actuarial 5-year overall survival rates were similar in the two groups: 81% (radiotherapy) and 85% (controls), p=0.31. Endometrial-cancer-related death rates were 9% in the radiotherapy group and 6% in the control group (p=0.37). Treatment-related complications occurred in 25% of radiotherapy patients, and in 6% of the controls (p<0.0001). Two-thirds of the complications were grade 1. Grade 3-4 complications were seen in eight patients, of which seven were in the radiotherapy group (2%). 2-year survival after vaginal recurrence was 79%, in contrast to 21% after pelvic recurrence or distant metastases. Survival after relapse was significantly (p=0.02) better for patients in the control group. Multivariate analysis showed that for locoregional recurrence, radiotherapy and age below 60 years were significant favourable prognostic factors. INTERPRETATION: Postoperative radiotherapy in stage-1 endometrial carcinoma reduces locoregional recurrence but has no impact on overall survival. Radiotherapy increases treatment-related morbidity. Postoperative radiotherapy is not indicated in patients with stage-1 endometrial carcinoma below 60 years and patients with grade-2 tumours with superficial invasion.


Subject(s)
Adenocarcinoma/radiotherapy , Adenocarcinoma/surgery , Carcinoma, Adenosquamous/radiotherapy , Carcinoma, Adenosquamous/surgery , Endometrial Neoplasms/radiotherapy , Endometrial Neoplasms/surgery , Adenocarcinoma/mortality , Adenocarcinoma/pathology , Aged , Carcinoma, Adenosquamous/mortality , Carcinoma, Adenosquamous/pathology , Endometrial Neoplasms/mortality , Endometrial Neoplasms/pathology , Female , Humans , Hysterectomy , Lymph Node Excision , Metaplasia , Middle Aged , Neoplasm Recurrence, Local/etiology , Neoplasm Staging , Ovariectomy , Prognosis , Prospective Studies , Radiotherapy, Adjuvant , Survival Analysis , Treatment Outcome
12.
J Clin Oncol ; 16(11): 3576-83, 1998 Nov.
Article in English | MEDLINE | ID: mdl-9817278

ABSTRACT

PURPOSE: To assess the efficacy of neoadjuvant methotrexate, cisplatin, and vinblastine (MCV) chemotherapy in patients with muscle-invading bladder cancer treated with selective bladder preservation. PATIENTS AND METHODS: One hundred twenty-three eligible patients with tumor, node, metastasis system clinical stage T2 to T4aNXMO bladder cancer were randomized to receive (arm 1, n=61 ) two cycles of MCV before 39.6-Gy pelvic irradiation with concurrent cisplatin 100 mg/m2 for two courses 3 weeks apart. Patients assigned to arm 2 (n=62) did not receive MCV before concurrent cisplatin and radiation therapy. Tumor response was scored as a clinical complete response (CR) when the cystoscopic tumor-site biopsy and urine cytology results were negative. The CR patients were treated with an additional 25.2 Gy to a total of 64.8 Gy and one additional dose of cisplatin. Those with less than a CR underwent cystectomy. The median follow-up of all patients who survived is 60 months. RESULTS: Seventy-four percent of the patients completed the protocol with, at most, minor deviations; 67% on arm 1 and 81% on arm 2. The actuarial 5-year overall survival rate was 49%; 48% in arm 1 and 49% in arm 2. Thirty-five percent of the patients had evidence of distant metastases at 5 years; 33% in arm 1 and 39% in arm 2. The 5-year survival rate with a functioning bladder was 38%, 36% in arm 1 and 40% in arm 2. None of these differences are statistically significant. CONCLUSION: Two cycles of MCV neoadjuvant chemotherapy were not shown to increase the rate of CR over that achieved with our standard induction therapy or to increase freedom from metastatic disease. There was no impact on 5-year overall survival.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Urinary Bladder Neoplasms/drug therapy , Urinary Bladder Neoplasms/radiotherapy , Aged , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Chemotherapy, Adjuvant , Cisplatin/administration & dosage , Combined Modality Therapy , Female , Hematologic Diseases/chemically induced , Humans , Male , Methotrexate/administration & dosage , Middle Aged , Nausea/chemically induced , Neoplasm Invasiveness , Survival Analysis , Time Factors , Vinblastine/administration & dosage
13.
Int J Radiat Oncol Biol Phys ; 40(1): 9-15, 1998 Jan 01.
Article in English | MEDLINE | ID: mdl-9422552

ABSTRACT

PURPOSE: To assess the degree to which the sociodemographic characteristics of patients enrolled in Radiation Therapy Oncology Group (RTOG) clinical trails are representative of the general population. METHODS AND MATERIALS: Sociodemographic data were collected on 4016 patients entered in 33 open RTOG studies between July 1991 and June 1994. The data analyzed included educational attainment, age, gender, and race. For comparison, we obtained similar data from the U.S. Department of Census. We also compared our RTOG data with Surveillance Epidemiology and End Results (SEER) data for patients who received radiation therapy, to determine how RTOG patients compared with cancer patients in general, and with patients with cancers at sites typically treated with radiotherapy. RESULTS: Overall, the sociodemographic characteristics of patients entered in RTOG trials were similar to those of the Census data. We found that, in every age group of African-American men and at nearly every level of educational attainment, the proportion of RTOG trial participants mirrored the proportion in the census data. Significant differences were noted only in the youngest category of African-American men, where the RTOG accrues more in the lower educational categories and fewer with college experience. For African-American women, we found a similar pattern in every age group and at each level of educational attainment. As with men, RTOG trials accrued a considerably larger proportion of younger, less educated African-American women than the census reported. Using SEER for comparison, the RTOG enrolled proportionately more African-American men to trials all cancer sites combined, and for prostate and head and neck cancer. In head and neck trials, the RTOG enrolled nearly twice as many African-American men than would be predicted by SEER data. In lung cancer trials, RTOG underrepresented African-American men significantly; however, there was no difference for brain cancer trials. There were no racial differences in RTOG accrual and SEER incidence data for women on trials in brain, lung, and head and neck cancer. However, the RTOG trials accrued nearly twice the proportion of African-American women in cervical cancer trials and in all sites combined, compared to the SEER data. CONCLUSIONS: Comparisons with the U.S. Census and SEER show that African-Americans are proportionally well represented in cancer clinical trials conducted by the Radiation Therapy Oncology Group. The comparative analysis indicates that all educational levels in each age group of African-Americans generally mirror the U.S. Census, with one exception. The exception is a significant overrepresentation of less-educated African-Americans in the youngest age category. This exception is counter to the expectation that better-educated patients are more likely to enroll in trials. When compared with SEER data, the RTOG trials either parallel or overrepresent African-American men and women, with the only exception being in lung cancer, where men are underrepresented. These results show that, in comparison to the Census and SEER data, the RTOG has fulfilled its commitment to enroll African-American patients in its clinical trials.


Subject(s)
Black or African American/statistics & numerical data , Clinical Trials as Topic/statistics & numerical data , Demography , Radiation Oncology/statistics & numerical data , White People/statistics & numerical data , Adult , Age Distribution , Aged , Educational Status , Female , Humans , Male , Middle Aged , Neoplasms/ethnology , Neoplasms/radiotherapy , SEER Program , Sex Distribution
14.
Clin Psychol Rev ; 17(7): 791-821, 1997 Nov.
Article in English | MEDLINE | ID: mdl-9397338

ABSTRACT

The purpose of this paper is to highlight the important role of individual difference factors in the experience of emotion. We begin by describing several commonalties across two major approaches to the study of emotion, namely, the neuropsychological and cognitive perspectives. Both approaches provide some degree of support for the role of individual differences and cognitive factors in the experience of emotion. This paper builds on these commonalities by reviewing personality and psychopathology findings that indicate the contribution of both positive and negative personality characteristics (e.g., extraversion, optimism vs. neuroticism, trait anxiety) to the types of cognitive appraisals and emotional responses exhibited by different individuals. A self-schema model of emotion is presented as a means of integrating more fully this individual differences perspective with a theory of emotion. In this model, self-schema content provides the basis for individual differences in underlying core themes and self-evaluative beliefs. The model describes how self-schema content distinctions across individuals may have a differential impact on the initial processing of an event, evaluation of this event with respect to the self, and emotional and behavioral output. Several examples are then presented to illustrate the increased predictability afforded by this individual differences-based self-schema model of emotion. The application of this model to treatment and prevention issues in clinical and health psychology is also briefly considered. Finally, the model is integrated with other theoretical perspectives on emotion by describing a number of additional research and theoretical implications. Emphasis is placed on the need for further clarification of both cognitive and emotional components of an individual differences perspective on the study of emotions.


Subject(s)
Emotions , Individuality , Cognition , Humans , Personality , Psychopathology , Psychotherapy , Self Concept
15.
J Dairy Sci ; 77(8): 2400-14, 1994 Aug.
Article in English | MEDLINE | ID: mdl-7962862

ABSTRACT

Additive and nonadditive genetic effects on lifetime yields of milk and milk components and lifetime profitability were estimated from 5070 cattle in a Holstein pureline, an Ayrshire-based pureline, and 10 crossbred groups of these purelines. Lifetime yields of milk, fat, protein, and lactose and lifetime milk value and annualized discounted net returns were analyzed. Lifetime yields, lifetime milk value, and annualized discounted net returns of the Holstein x Ayrshire-based line F1 and an F1 x (F1 x F1) cross were not significantly different from those for the Holstein pureline. Net reproductive rate for F1 females was 9% greater than that of contemporary Holsteins. The Holstein pureline was superior to the Ayrshire-based pureline for direct additive genetic merit for all traits. Heterosis for the lifetime traits ranged from 16.6% for lifetime milk yield to 20.6% for annualized discounted net returns. Cytoplasmic maternal effect on annualized discounted net return was significant and favored the Ayrshire-based line. Potential economic benefit may derive from development of a crossbred cow that is superior to Holsteins. Maximum exploitation of additive and nonadditive genetic effects on lifetime yields and profitability appears to favor a rotational crossbreeding system with two breeds.


Subject(s)
Cattle/genetics , Dairying/economics , Animals , Breeding/methods , Breeding/statistics & numerical data , Crosses, Genetic , Female , Lactation/genetics , Lactose/metabolism , Lipid Metabolism , Male , Milk/metabolism , Milk Proteins/metabolism
16.
J Dairy Sci ; 75(5): 1273-80, 1992 May.
Article in English | MEDLINE | ID: mdl-1597582

ABSTRACT

Early part records for milk yield and feed consumption of 2230 first lactation purebred and crossbred dairy cows were analyzed to evaluate various measures of feed efficiency. Corrected milk yield was estimated by adjusting the second 8 wk of milk yield for differences in weight of TDN consumed during wk 9 to 16, percentage of TDN derived from concentrate, and BW.75. Corrected milk yield is an estimate assuming that cows are the same size and consume the same amount of feed. Hence, it represents an expression of feed efficiency. Net feed efficiency, gross efficiency, corrected milk yield, and wk 9 to 16 milk were analyzed simultaneously. Coefficient of determination for net efficiency (.51) and gross efficiency (.72) were lower than that of milk (.82), whereas corrected milk yield had a coefficient of determination similar to that of milk. Hence, the use of ratios to define feed efficiency was less accurate than using corrected milk yield. Effects of genetic groups, stations, season of freshening, year of freshening, and heterosis were similar for gross efficiency and corrected milk yield, but different from those for milk. Therefore, corrected milk yield performed the same function as feed efficiency with higher accuracy.


Subject(s)
Cattle/physiology , Eating , Lactation , Milk/metabolism , Animals , Breeding , Cattle/genetics , Female , Genotype , Hybrid Vigor , Lactation/genetics , Least-Squares Analysis
17.
World J Microbiol Biotechnol ; 7(2): 164-70, 1991 Mar.
Article in English | MEDLINE | ID: mdl-24424928

ABSTRACT

A number of research institutions and both local and international agencles in Latin America are using biotechnology as part of an effort to enhance agricultural productivity. However, it is very much an open question as to whether all of these various organizations can provide the best means of realizing this goal. Latin American countries vary dramatically in their knowledge base and current use of modern biotechnology. Thus, while some countries lack the ability to develop, or possibly even implement, many aspects of modern biotechnology, others are quite advanced in this regard. This review provides a somewhat selective overview of current research in the area of agricultural biotechnology in Mexico, Costa Rica and Ecuador, with emphasis on how the existing agencies and institutions have responded to the challenge of biotechnology. In addition, general strategies for the development of agricultural biotechnology in these countries are presented and discussed.

18.
J Dairy Sci ; 72(11): 3085-90, 1989 Nov.
Article in English | MEDLINE | ID: mdl-2625498

ABSTRACT

Data from 889 cows at five research stations of Agriculture Canada were used to study the effects of alpha s1-casein, beta-casein, kappa-casein, and beta-lactoglobulin loci on herdlife and total yield over fixed parities (one, two, and three parity) and to a fixed age (36, 48, and 61 mo). Actual yields of all cows were utilized to compute total milk regardless of lactational length. The model consisted of station, breed, year of birth, season of birth, and milk protein types with age at first calving as a covariate. Of the four milk protein types studied, only the kappa-casein locus had significant effects on fixed parity and fixed age total milk and herdlife. Cows with BB kappa-casein type outproduced those with AB or AA kappa-casein types in three parity total milk by 963 and 1657 kg, respectively. Considering total milk accumulated up to 61 mo of age in life, cows with BB kappa-casein type outperformed their counterparts with AB or AA kappa-casein types by 1050 and 1923 kg, respectively. Complete replacement of A by B allele at kappa-casein locus would result in an increase of 1657 kg in three parity total milk and an increase of 1923 kg in 61-mo total milk. The moderate gene frequency of kappa-casein B allele in the current dairy population can be increased to improve lifetime total milk to the benefit of the dairy industry.


Subject(s)
Caseins/genetics , Cattle/physiology , Lactation/genetics , Lactoglobulins/genetics , Alleles , Analysis of Variance , Animals , Breeding , Caseins/analysis , Cattle/genetics , Female , Lactoglobulins/analysis , Least-Squares Analysis , Milk/analysis , Parity , Pregnancy
19.
J Dairy Sci ; 71(4): 1011-24, 1988 Apr.
Article in English | MEDLINE | ID: mdl-3392297

ABSTRACT

The proportional hazards model with censoring was used to assess the effects of breeding value, disease, calving, size, and udder and lactation traits on length of herdlife of 3881 heifers in five herds. Data were recorded over 10 yr from three lines: a Holstein line, an Ayrshire-based line, and a crossbred line. Influences on survival were assessed from data collected at birth, 34, 50, and 82 wk, first freshening, and at 112 and 308 d postpartum. Median estimated herdlife (age at 50% culling) was 3.9 yr for animals alive at first freshening and increased to 4.3 yr for those that completed a first lactation (308 d postpartum). Herds differed greatly in the pattern of culling after freshening. Crossbred females had 21 wk longer median estimated herdlife than the mean of the purelines at 308 d postpartum. Individual milk yield was positively associated with longevity and had the greatest impact on length of herdlife. Abortion and fertility measured as days to last insemination were negatively associated with length of herdlife. Large heifers tended to have increased longevity. High feed intake postpartum was associated with reduced length of herdlife. Objective measures of conformation, which included measurements of the udder, were not important in determining herdlife.


Subject(s)
Cattle/physiology , Crosses, Genetic , Longevity , Models, Biological , Animals , Female
20.
J Dairy Sci ; 71(4): 1000-10, 1988 Apr.
Article in English | MEDLINE | ID: mdl-3392296

ABSTRACT

Data on 3957 heifers from the Holstein H line, Ayrshire-based A line, and C line (crossbreds between H and A lines) were used. Growth, feed consumption, and feed efficiency from 26 to 34 wk were examined. The full model included the fixed effects of herd, year of birth, season of birth, and additive, maternal, and heterotic genetic effects with 26-wk weight as a covariate. Heterotic and maternal effects were not significant. Adjusted for the 26-wk weight covariate, H line heifers gained 3 kg more than A line heifers with C line heifers intermediate. Adjusted for 26 and 34-wk weight covariates, H line heifers ate 2 kg less TDN than A line heifers and, hence, were more efficient. Correlations among traits were estimated using the residual variance-covariance matrix from the full model. Body weight at 34 wk was correlated with 26-wk weight (r = .88) but essentially independent of rate of gain (r = .02). It was correlated with feed consumed (r = .51) and negatively associated with gain/feed consumed (r = -.25). Gain was correlated (r = .84) with gain/feed consumed but mildly so (r = .28) with feed consumed. Feed consumption was negatively correlated (r = -.25) with gain/feed consumed when the 26-wk weight covariate was included but became much larger (r = -.95) when both 26 and 34 wk weight covariates were included. Although genetic differences in feed consumption and feed efficiency of growing heifers exist, these are small and closely associated with weights and weight gains.


Subject(s)
Animal Nutritional Physiological Phenomena , Body Weight , Cattle/growth & development , Crosses, Genetic , Animals , Female
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